Boil 4 cups of water
Add 1/2 cup sugar and stir until dissolved
Add 4–6 black tea or green tea bags
Steep for 10–15 minutes
Remove tea bags
Add 8 cups of cool, filtered water
Let the tea cool to room temperature
Pour the tea into a clean glass jar
Add 1 cup of plain, unflavored starter kombucha
Add 1 SCOBY to the jar
Cover the jar with a clean cloth or paper towel
Secure the cover with a rubber band
Keep the jar in a warm, dark place
Ferment for 7–14 days
Taste the kombucha after 7 days
Ferment longer for a more sour taste
Remove the SCOBY and save 1 cup of kombucha for the next batch
Bottle the kombucha
Add fruit, juice, or ginger if desired
Seal the bottles tightly
Leave bottles at room temperature for 1–3 days for carbonation
Refrigerate the bottles
Chill before drinking